JP2021125488A - Ceramic joint, electrostatic chuck device, and manufacturing method of ceramic joint - Google Patents

Abstract

To provide a ceramic joint, an electrostatic chuck device, and a manufacturing method of the ceramic joint which suppress dielectric breakdown (discharge) at the joint interface between a ceramic plate and a conductive layer.SOLUTION: A ceramic joint 1 includes a pair of ceramic plates 2 and 3 including a conductive substance, a conductive layer 4 and an insulating layer 5 interposed between the pair of ceramic plates 2 and 3, and intermediate layers 6 and 7 that are interposed between the pair of ceramic plates 2 and 3 and the conductive layer 4, and are in contact with the pair of ceramic plates 2 and 3 and the conductive layer 4.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ceramic joint, an electrostatic chuck device, and a method for manufacturing the ceramic joint.

Conventionally, in a semiconductor manufacturing process for manufacturing semiconductor devices such as ICs, LSIs, and VLSIs, a plate-shaped sample such as a silicon wafer is fixed to an electrostatic chuck member having an electrostatic chuck function by electrostatic adsorption to determine a predetermined value. Processing is applied.
For example, when the plate-shaped sample is subjected to an etching treatment or the like in a plasma atmosphere, the surface of the plate-shaped sample becomes high due to the heat of the plasma, and a problem such as tearing (burst) of the resist film on the surface occurs.
Therefore, an electrostatic chuck device is used to maintain the temperature of this plate-shaped sample at a desired constant temperature. The electrostatic chuck device uses a silicone-based adhesive on a temperature control base member in which a flow path for circulating a cooling medium for temperature control is formed inside a metal member on the lower surface of the electrostatic chuck member. It is a device that is joined and integrated through.
In this electrostatic chuck device, a cooling medium for temperature adjustment is circulated in the flow path of the temperature adjustment base member to exchange heat, and the temperature of the plate-shaped sample fixed on the upper surface of the electrostatic chuck member is preferably constant. Electrostatic adsorption is performed while maintaining the temperature, and various plasma treatments are applied to this plate-shaped sample.

By the way, the electrostatic chuck member of the electrostatic chuck device is required to have corrosion resistance, heat resistance, plasma resistance, durability against a load of a thermal cycle, and the like. In order to realize an electrostatic chuck device having such excellent performance, an electrostatic chuck substrate made of a composite dielectric ceramic in which a conductive material is added to an insulating ceramic material, and an electrostatic chuck substrate incorporated in the electrostatic chuck substrate. An electrostatic chuck member including an internal electrode and a power feeding terminal provided in contact with the internal electrode is known (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2003-152062 Japanese Unexamined Patent Publication No. 2007-051045

The internal electrode of the electrostatic chuck electrode built-in type susceptor of Patent Document 1 and Patent Document 2 is not particularly limited, but is a highly conductive high melting point material, and is a composite containing an insulating ceramic material and a conductive high melting point material. It may be a sintered body. Since the bonding surface between the composite dielectric ceramics and the internal electrode is generally bonded after the surface has been polished, a conductive material is exposed at the bonding interface between the electrostatic chuck substrate and the internal electrode, and the internal electrode and the bonding surface are exposed. Conductive paths are likely to be formed at the interface between the two, and the insulating property is low. Therefore, there is a problem that dielectric breakdown (discharge) occurs at the bonding interface between the composite dielectric ceramic and the internal electrode.

The present invention has been made in view of the above circumstances, and is an electrostatic chuck device including a ceramic joint and a ceramic joint that suppresses dielectric breakdown (discharge) at the joint interface between the ceramic plate and the conductive layer. And it is an object of the present invention to provide a method for manufacturing a ceramic joint.

In order to solve the above problems, one aspect of the present invention includes a pair of ceramic plates containing a conductive substance, a conductive layer and an insulating layer interposed between the pair of ceramic plates, and the pair of ceramic plates and the conductive layer. Provided is a ceramic joint comprising the pair of ceramic plates and an intermediate layer in contact with the conductive layer.

In one aspect of the present invention, the conductive layer may be composed of a conductive substance and an insulating substance, and the insulating layer and the intermediate layer may be composed of an insulating substance.

In one aspect of the present invention, when the thickness of the conductive layer is t1 and the thickness of the intermediate layer is t2, the thickness ratio R1 of the intermediate layer defined by the following formula (1) is 3%. It may be the above.
R1 = t2 / t1 × 100 (%) (1)

In one aspect of the present invention, the average primary particle size of the insulating substance constituting the insulating layer may be 1.6 μm or more and 10.0 μm or less.

In one aspect of the present invention, the ceramic plate may be a composite of aluminum oxide and silicon carbide.

In one aspect of the present invention, the insulating substance constituting the conductive layer, the insulating layer and the intermediate layer may be aluminum oxide.

In one aspect of the present invention, the conductive material constituting the conductive _{layer, Mo 2 C, Mo, WC} , W, is selected TaC, Ta, SiC, carbon black, from the group consisting of carbon nanotubes and carbon nanofibers It may be at least one kind.

One aspect of the present invention is an electrostatic chuck device in which an electrostatic chuck member made of ceramics and a temperature control base member made of metal are joined via an adhesive layer, and the electrostatic chuck member. Provides an electrostatic chuck device made of a ceramics bonded body according to one aspect of the present invention.

One aspect of the present invention includes a step of applying an intermediate layer forming paste on one surface of a first ceramic plate containing a conductive substance to form a first intermediate layer coating film, and the first intermediate layer. The step of applying the conductive layer forming paste to the surface of the coating film opposite to the surface in contact with the first ceramic plate to form the conductive layer coating film, and the first intermediate layer of the conductive layer coating film. The step of applying the intermediate layer forming paste to the surface opposite to the surface in contact with the coating film to form the second intermediate layer coating film and the step of contacting the conductive layer coating film of the second intermediate layer coating film. A step of laminating a second ceramic plate containing a conductive substance on a surface opposite to the surface, the first ceramic plate, the first intermediate layer coating film, the conductive layer coating film, and the second Provided is a method for producing a ceramics bonded body, which comprises a step of pressurizing the laminate including the intermediate layer coating film and the second ceramics plate in the thickness direction while heating.

According to the present invention, there is provided a ceramic joint that suppresses dielectric breakdown (discharge) at the joint interface between the ceramic plate and the conductive layer, an electrostatic chuck device including the ceramic joint, and a method for manufacturing the ceramic joint. be able to.

It is sectional drawing which shows the ceramics bonded body which concerns on one Embodiment of this invention. It is sectional drawing which shows the ceramics bonded body which concerns on one Embodiment of this invention. It is sectional drawing which shows the electrostatic chuck device which concerns on one Embodiment of this invention.

An embodiment of the ceramic joint, the electrostatic chuck device, and the method for manufacturing the ceramic joint of the present invention will be described.
It should be noted that the present embodiment is specifically described in order to better understand the gist of the invention, and is not limited to the present invention unless otherwise specified.

[Ceramics joint]
(First Embodiment)
Hereinafter, the ceramic joint according to the embodiment of the present invention will be described with reference to FIG.
In all the drawings below, the dimensions and ratios of the components are appropriately different in order to make the drawings easier to see.

FIG. 1 is a cross-sectional view showing the ceramic joint of the present embodiment. As shown in FIG. 1, the ceramic joint 1 of the present embodiment has a pair of ceramic plates 2 and 3 containing a conductive substance, and a conductive layer 4 and an insulating layer 5 interposed between the pair of ceramic plates 2 and 3. And the intermediate layers 6 and 7 interposed between the pair of ceramic plates 2 and 3 and the conductive layer 4 and the insulating layer 5 and in contact with the pair of ceramic plates 2 and 3 and the conductive layer 4 and the insulating layer 5. There is.
Hereinafter, the ceramic plate 2 is referred to as a first ceramic plate 2, the ceramic plate 3 is referred to as a second ceramic plate 3, the intermediate layer 6 is referred to as a first intermediate layer 6, and the intermediate layer 7 is referred to as a second intermediate layer 7.
As shown in FIG. 1, the ceramic joint 1 includes a first ceramic plate 2, a first intermediate layer 6, a conductive layer 4, an insulating layer 5, a second intermediate layer 7, and a second ceramic. The plates 3 are laminated in this order. That is, in the ceramic joint body 1, the first ceramic plate 2 and the second ceramic plate 3 are joined and integrated via the first intermediate layer 6, the conductive layer 4, the insulating layer 5, and the second intermediate layer 7. It is a ceramicized joint.

The first ceramic plate 2 and the second ceramic plate 3 have the same shape of the overlapping surface.
The thicknesses of the first ceramic plate 2 and the second ceramic plate 3 are not particularly limited, and are appropriately adjusted according to the use of the ceramic joint 1.

The first ceramic plate 2 and the second ceramic plate 3 have the same composition or the same main component. The first ceramic plate 2 and the second ceramic plate 3 are made of a composite of an insulating substance and a conductive substance. The insulating material contained in the first ceramic plate 2 and the second ceramic plate 3 is not particularly limited, and is, for example, aluminum oxide (Al ₂ O ₃ ), aluminum nitride (Al N), yttrium oxide (Y ₂ O _3). ), Yttrium aluminum garnet (YAG) and the like. The conductive material contained in the first ceramic plate 2 and the second ceramic plate 3 is not particularly limited, but is, for example, silicon carbide (SiC), titanium oxide (TIO ₂ ), titanium nitride (TiN), or carbide. Examples thereof include titanium (TiC), carbon (C), carbon nanotubes (CNT), carbon nanofibers, rare earth oxides, and rare earth fluorides.

The materials of the first ceramic plate 2 and the second ceramic plate 3 have a volume resistivity of 10 ¹³ Ω · cm or more and 10 ¹⁵ Ω · cm or less, have mechanical strength, and are corrosive. It is not particularly limited as long as it has durability against gas and its plasma. Examples of such a material include an aluminum oxide (Al ₂ O ₃ ) sintered body, an aluminum nitride (AlN) sintered body, an aluminum oxide (Al ₂ O ₃ ) -silicon carbide (SiC) composite sintered body, and the like. there may be mentioned, dielectric properties at high temperatures, high corrosion resistance, plasma resistance, from the viewpoint of heat resistance, aluminum oxide (Al 2 O _{3) -} silicon carbide (SiC) composite sintered body is preferable.

The conductive layer 4 is an electrode for generating plasma for generating plasma by energizing high-frequency power to generate plasma, and an electrode for electrostatic chuck for generating electric charge and fixing a plate-shaped sample by electrostatic attraction. It is used as a heater electrode or the like for heating a plate-shaped sample by generating heat by energization. The shape of the conductive layer 4 (the shape when the conductive layer 4 is viewed in a plan view (viewed from the thickness direction)) and the size (the thickness and the shape when the conductive layer 4 is viewed in a plan view (viewed from the thickness direction)). The area) is not particularly limited, and is appropriately adjusted according to the use of the ceramic joint 1.

The conductive layer 4 is composed of a conductive substance and an insulating substance.

The conductive substance contained in the conductive layer 4 is molybdenum carbide (Mo ₂ C), molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), silicon carbide (SiC). ), Carbon black, carbon nanotubes and carbon nanofibers are preferably at least one selected from the group. When the conductive substance contained in the conductive layer 4 is at least one selected from the group consisting of the substances, the conductivity of the conductive layer can be ensured.

The insulating substance contained in the conductive layer 4 is not particularly limited, and is, for example, aluminum oxide (Al ₂ O ₃ ), aluminum nitride (Al N), yttrium oxide (Y ₂ O ₃ ), yttrium aluminum garnet (YAG). And so on. The insulating substance contained in the conductive layer 4 is preferably matched with the main components of the first ceramic plate 2 and the second ceramic plate 3.
Since the conductive layer 4 is made of a conductive substance and an insulating substance, the bonding strength between the first ceramic plate 2 and the second ceramic plate 3 and the mechanical strength as an electrode are increased.
Since the insulating substance contained in the conductive layer 4 is aluminum oxide (Al ₂ O ₃ ), the dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance are maintained.

The ratio (blending ratio) of the contents of the conductive substance and the insulating substance in the conductive layer 4 is not particularly limited, and is appropriately adjusted according to the use of the ceramic joint 1.

The insulating layer 5 is provided to join the boundary portion between the first ceramic plate 2 and the second ceramic plate 3, that is, the outer edge region other than the conductive layer 4 forming portion. The shape of the insulating layer 5 (the shape when the insulating layer 5 is viewed in a plan view (viewed from the thickness direction)) is not particularly limited, and is appropriately adjusted according to the shape of the conductive layer 4.
In the ceramic joint 1 of the present embodiment, the thickness of the insulating layer 5 is equal to the thickness of the conductive layer 4.

The insulating layer 5 is made of an insulating substance.
The insulating substance constituting the insulating layer 5 is not particularly limited, but is preferably the same as the main components of the first ceramic plate 2 and the second ceramic plate 3, for example, aluminum oxide (Al ₂ O ₃ ). , aluminum nitride (AlN), yttrium oxide _{(Y 2 O} 3), yttrium aluminum garnet (YAG), and the like. The insulating substance constituting the insulating layer 5 is preferably _{aluminum oxide (Al 2} O _3). Since the insulating substance constituting the insulating layer 5 is aluminum oxide (Al ₂ O ₃ ), the dielectric property at high temperature, high corrosion resistance, plasma resistance, and heat resistance are maintained.

The average primary particle size of the insulating substance constituting the insulating layer 5 is preferably 1.6 μm or more and 10.0 μm or less, and more preferably 1.6 μm or more and 6.0 μm or less.
When the average primary particle size of the insulating substance constituting the insulating layer 5 is 1.6 μm or more, sufficient withstand voltage resistance can be obtained. On the other hand, when the average primary particle size of the insulating substance constituting the insulating layer 5 is 10.0 μm or less, the processability such as grinding is good.

The first intermediate layer 6 is provided between the first ceramic plate 2 and the conductive layer 4 and the insulating layer 5 to insulate the first ceramic plate 2 and the conductive layer 4. The second intermediate layer 7 is provided between the second ceramic plate 3 and the conductive layer 4 and the insulating layer 5 to insulate the second ceramic plate 3 and the conductive layer 4. The shapes of the first intermediate layer 6 and the second intermediate layer 7 (the shape when the first intermediate layer 6 and the second intermediate layer 7 are viewed in a plan view (viewed from the thickness direction)) are particularly limited. Instead, it is appropriately adjusted according to the shapes of the conductive layer 4 and the insulating layer 5.

The thickness of the first intermediate layer 6 and the thickness of the second intermediate layer 7 may be different from each other or may be equal, but are preferably equal.
When the thickness of the conductive layer 4 is t1 and the sum of the thickness of the first intermediate layer 6 and the thickness of the second intermediate layer 7 is t2, the thickness of the conductive layer 4 defined by the following formula (1) The ratio (R1) of the total thickness of the first intermediate layer 6 and the thickness of the second intermediate layer 7 to t1 is preferably 3% or more, and more preferably 8% or more.
R1 = t2 / t1 × 100 (%) (1)
When R1 is 3% or more, a conductive path is not formed at the interface between the ceramic plate and the internal electrode, so that sufficient side dielectric strength can be obtained.
Further, R1 is preferably 50% or less, and more preferably 40% or less. If R1 exceeds 50%, the conductive layer 4 cannot obtain a sufficient thickness, which is not preferable because uniform adsorption force, temperature soaking property, and the like are lowered.

The first intermediate layer 6 and the second intermediate layer 7 are made of an insulating material.
The insulating material constituting the first intermediate layer 6 and the second intermediate layer 7 is not particularly limited, but is preferably the same as the main components of the first ceramic plate 2 and the second ceramic plate 3, for example. Examples thereof include aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), yttrium oxide (Y ₂ O ₃ ), yttrium aluminum garnet (YAG) and the like. The insulating substance constituting the first intermediate layer 6 and the second intermediate layer 7 is preferably _{aluminum oxide (Al 2} O _3). Since the insulating substance constituting the first intermediate layer 6 and the second intermediate layer 7 is aluminum oxide (Al ₂ O ₃ ), the dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance are improved. Be kept.

According to the ceramic joint 1 of the present embodiment, the pair of ceramic plates 2 and 3 containing a conductive substance, the conductive layer 4 and the insulating layer 5 interposed between the ceramic plates 2 and 3, and the ceramic plates 2 and 3 The ceramic plates 2 and 3 and the intermediate layers 6 and 7 in contact with the ceramic plates 2 and 3 are provided between the ceramic plates 2 and 3 and the conductive layers 4, so that the ceramic plates 2 and 3 and the conductive layer 4 are insulated by the intermediate layers 6 and 7. Therefore, it is possible to suppress the occurrence of dielectric breakdown (discharge) at the bonding interface between the ceramic plates 2 and 3 and the conductive layer 4.

(Second Embodiment)
FIG. 2 is a cross-sectional view showing the ceramic joint of the present embodiment. In FIG. 2, the same components as those of the ceramic joint shown in FIG. 1 are designated by the same reference numerals, and redundant description will be omitted.
As shown in FIG. 2, the ceramic joint 10 of the present embodiment has a pair of ceramic plates 2 and 3 containing a conductive substance, and a conductive layer 4 and an insulating layer 5 interposed between the pair of ceramic plates 2 and 3. And intermediate layers 6 and 7 which are interposed between the pair of ceramic plates 2 and 3 and the conductive layer 4 and are in contact with the pair of ceramic plates 2 and 3 and the conductive layer 4.
As shown in FIG. 2, the ceramic joint 10 has a first ceramic plate 2, a first intermediate layer 6, a conductive layer 4, and a second intermediate layer in a region where the conductive layer 4 is provided. 7 and the second ceramic plate 3 are laminated in this order. Further, in the ceramic joint 10, the first ceramic plate 2, the insulating layer 5, and the second ceramic plate 3 are laminated in this order in the region where the insulating layer 5 is provided. That is, in the ceramic joint 10, in the region where the conductive layer 4 is provided, the first ceramic plate 2 and the second ceramic plate 3 are the first intermediate layer 6, the conductive layer 4 and the second intermediate layer. In the region where the insulating layer 5 is provided, the first ceramic plate 2 and the second ceramic plate 3 are joined and integrated via the insulating layer 5. It is a joined body.

According to the ceramic joint body 10 of the present embodiment, the same effect as that of the ceramic joint body 1 of the first embodiment can be obtained.

[Manufacturing method of ceramic joint]
The method for producing a ceramic joint of the present embodiment is a step of applying a paste for forming an intermediate layer to one surface of a first ceramic plate containing a conductive substance to form a first intermediate layer coating film (hereinafter referred to as a step). The conductive layer coating film is coated with the conductive layer forming paste on the surface of the first intermediate layer coating film opposite to the surface in contact with the first ceramic plate. (Hereinafter referred to as "second step") and the intermediate layer forming paste are applied to the surface of the conductive layer coating film on the side opposite to the surface in contact with the first intermediate layer coating film. Then, the step of forming the second intermediate layer coating film (hereinafter referred to as "third step") and the surface of the second intermediate layer coating film on the opposite side to the surface in contact with the conductive layer coating film are opposite to each other. A step of laminating a second ceramic plate containing a conductive substance on a surface (hereinafter referred to as a "fourth step"), the first ceramic plate, the first intermediate layer coating film, and the conductive layer. A step of pressurizing the laminate including the coating film, the second intermediate layer coating film, and the second ceramic plate in the thickness direction while heating (hereinafter, referred to as "fifth step"). Has.

Hereinafter, the method for manufacturing the ceramic joint of the present embodiment will be described with reference to FIG.
In the first step, a paste for forming an intermediate layer is applied to one surface 2a of the first ceramic plate 2 by a coating method such as a screen printing method to form a coating film (first intermediate layer 6). Intermediate layer coating film) is formed.
As the paste for forming the intermediate layer, a paste in which an insulating substance forming the first intermediate layer 6 is dispersed in a solvent is used.
Isopropyl alcohol or the like is used as the solvent contained in the paste for forming the intermediate layer.

In the second step, the surface of the coating film to be the first intermediate layer 6 formed on one surface 2a of the first ceramic plate 2 by a coating method such as a screen printing method and the surface in contact with the first ceramic plate 2 Applyes a conductive layer forming paste to the opposite surface 6a to form a coating film (conductive layer coating film) to be the conductive layer 4.
As the paste for forming the conductive layer, a paste in which the conductive substance and the insulating substance forming the conductive layer 4 are dispersed in a solvent is used.
Isopropyl alcohol or the like is used as the solvent contained in the pace for forming the conductive layer.

Further, in the second step, the first ceramic plate 2 of the coating film to be the first intermediate layer 6 formed on one surface 2a of the first ceramic plate 2 is brought into contact with the first ceramic plate 2 by a coating method such as a screen printing method. An insulating layer forming paste is applied to the surface 6a on the side opposite to the surface to form a coating film (insulating layer coating film) to be the insulating layer 5.
As the paste for forming the insulating layer, a paste in which the insulating substance forming the insulating layer 5 is dispersed in a solvent is used.
Isopropyl alcohol or the like is used as the solvent contained in the pace for forming the insulating layer.

In the third step, by a coating method such as a screen printing method, the surface 4a on the side opposite to the surface in contact with the coating film to be the first intermediate layer 6 of the coating film to be the conductive layer 4 and the insulating layer 5 are formed. The intermediate layer forming paste is applied to the surface 5a on the side opposite to the surface in contact with the coating film to be the first intermediate layer 6 of the coating film, and the coating film to be the second intermediate layer 7 (second intermediate layer coating). Membrane) is formed.
As the paste for forming the intermediate layer, a paste in which an insulating substance forming the second intermediate layer 7 is dispersed in a solvent is used.
Isopropyl alcohol or the like is used as the solvent contained in the paste for forming the intermediate layer.

In the fourth step, the second ceramic plate 3 is attached to the surface 3a opposite to the surface in contact with the coating film to be the conductive layer 4 and the coating film to be the insulating layer 5 of the coating film to be the second intermediate layer 7. Laminate.

In the fifth step, the first ceramic plate 2, the coating film to be the first intermediate layer 6, the coating film to be the conductive layer 4, the coating film to be the insulating layer 5, and the coating film to be the second intermediate layer 7. The laminate including the second ceramic plate 3 and the second ceramic plate 3 is pressed in the thickness direction while being heated. The atmosphere when the laminate is pressurized in the thickness direction while being heated is preferably a vacuum or an inert atmosphere such as _{Ar, He, N 2.}

The temperature for heating the laminate (heat treatment temperature) is preferably 1600 ° C. or higher and 1900 ° C. or lower, and more preferably 1650 ° C. or higher and 1850 ° C. or lower.
When the temperature for heating the laminate is 1600 ° C. or higher and 1900 ° C. or lower, the solvent contained in each coating film is volatilized to form a second space between the first ceramic plate 2 and the second ceramic plate 3. The intermediate layer 7, the conductive layer 4, the insulating layer 5, and the second intermediate layer 7 can be formed. Further, the first ceramic plate 2 and the second ceramic plate 3 can be joined and integrated via the second intermediate layer 7, the conductive layer 4, the insulating layer 5, and the second intermediate layer 7.

The pressure (pressurizing pressure) for pressurizing the laminated body in the thickness direction is preferably 1.0 MPa or more and 50.0 MPa or less, and more preferably 5.0 MPa or more and 20.0 MPa or less.
When the pressure for pressurizing the laminate in the thickness direction is 1.0 MPa or more and 50.0 MPa or less, the second intermediate layer 7 is in close contact with each other between the first ceramic plate 2 and the second ceramic plate 3. , The conductive layer 4, the insulating layer 5 and the second intermediate layer 7 can be formed. Further, the first ceramic plate 2 and the second ceramic plate 3 can be joined and integrated via the second intermediate layer 7, the conductive layer 4, the insulating layer 5, and the second intermediate layer 7.

[Electrostatic chuck device]
Hereinafter, the electrostatic chuck device according to the embodiment of the present invention will be described with reference to FIG.

FIG. 3 is a cross-sectional view showing the electrostatic chuck device of this embodiment. In FIG. 3, the same components as those of the ceramic joint shown in FIG. 1 are designated by the same reference numerals, and redundant description will be omitted.
As shown in FIG. 3, the electrostatic chuck device 100 of the present embodiment includes a disk-shaped electrostatic chuck member 102 and a disk-shaped temperature control base member that adjusts the electrostatic chuck member 102 to a desired temperature. It has 103, and an adhesive layer 104 that joins and integrates the electrostatic chuck member 102 and the temperature adjusting base member 103. In the electrostatic chuck device 100 of the present embodiment, the electrostatic chuck member 102 is composed of, for example, the ceramic joint body 1 or the ceramic joint body 1 of the above-described embodiment. Here, a case where the electrostatic chuck member 102 is made of the ceramic joint 1 will be described.

In the following description, the mounting surface 111a side of the mounting plate 111 may be referred to as "upper" and the temperature adjusting base member 103 side may be referred to as "lower" to represent the relative positions of each configuration.

[Electrostatic chuck member]
The electrostatic chuck member 102 has a mounting plate 111 whose upper surface is made of ceramics having a mounting surface 111a on which a plate-shaped sample such as a semiconductor wafer is mounted, and a surface opposite to the mounting surface 111a of the mounting plate 111. A support plate 112 provided on the side, an electrostatic adsorption electrode 113 sandwiched between the mounting plate 111 and the support plate 112, and an electrostatic adsorption electrode 113 sandwiched between the mounting plate 111 and the support plate 112 for electrostatic adsorption. It has an annular insulating material 114 surrounding the periphery of the electrode 113, and a power feeding terminal 116 provided in a fixing hole 115 of the temperature control base member 103 so as to be in contact with the electrostatic adsorption electrode 113.
In the electrostatic chuck member 102, the mounting plate 111 corresponds to the second ceramic plate 3, the support plate 112 corresponds to the first ceramic plate 2, and the electrostatic adsorption electrode 113 corresponds to the conductive electrode 113. It corresponds to the layer 4, and the insulating material 114 corresponds to the above-mentioned insulating layer 5.

[Mounting board]
A large number of protrusions for supporting a plate-shaped sample such as a semiconductor wafer are erected on the mounting surface 111a of the mounting plate 111 (not shown). Further, on the peripheral edge of the mounting surface 111a of the mounting plate 111, an annular protrusion having a quadrangular cross section is provided so as to go around the peripheral edge so that cooling gas such as helium (He) does not leak. You may be. Further, in the region surrounded by the annular protrusions on the mounting surface 111a, a plurality of protrusions having the same height as the annular protrusions, having a circular cross section and a substantially rectangular vertical cross section are provided. You may be.

The thickness of the mounting plate 111 is preferably 0.3 mm or more and 3.0 mm or less, and more preferably 0.5 mm or more and 1.5 mm or less. When the thickness of the mounting plate 111 is 0.3 mm or more, the withstand voltage resistance is excellent. On the other hand, if the thickness of the mounting plate 111 is 3.0 mm or less, the electrostatic attraction force of the electrostatic chuck member 102 does not decrease, and the plate is mounted on the mounting surface 111a of the mounting plate 111. The temperature of the plate-shaped sample being processed can be maintained at a preferable constant temperature without reducing the thermal conductivity between the shaped sample and the temperature adjusting base member 103.

[Support plate]
The support plate 112 supports the mounting plate 111 and the electrostatic adsorption electrode 113 from below.

The thickness of the support plate 112 is preferably 0.3 mm or more and 3.0 mm or less, and more preferably 0.5 mm or more and 1.5 mm or less. If the thickness of the support plate 112 is 0.3 mm or more, a sufficient withstand voltage can be secured. On the other hand, if the thickness of the support plate 112 is 3.0 mm or less, the electrostatic attraction force of the electrostatic chuck member 102 does not decrease, and the plate shape is mounted on the mounting surface 111a of the mounting plate 111. The temperature of the plate-shaped sample being processed can be maintained at a preferable constant temperature without reducing the thermal conductivity between the sample and the temperature adjusting base member 103.

[Electrode for electrostatic adsorption]
In the electrostatic adsorption electrode 113, by applying a voltage, an electrostatic adsorption force for holding the plate-shaped sample on the mounting surface 111a of the mounting plate 111 is generated.

The thickness of the electrostatic adsorption electrode 113 is preferably 5 μm or more and 200 μm or less, and more preferably 10 μm or more and 100 μm or less. When the thickness of the electrostatic adsorption electrode 113 is 5 μm or more, sufficient conductivity can be ensured. On the other hand, if the thickness of the electrostatic adsorption electrode 113 is 200 μm or less, the thermal conductivity between the plate-shaped sample mounted on the mounting surface 111a of the mounting plate 111 and the temperature adjusting base member 3 is high. The temperature of the plate-shaped sample being processed can be maintained at a desired constant temperature without lowering. In addition, plasma permeability can be stably generated without deterioration.

[Insulating material]
The insulating material 114 surrounds the electrostatic adsorption electrode 113 and protects the electrostatic adsorption electrode 113 from corrosive gas and its plasma.
The mounting plate 111 and the support plate 112 are joined and integrated by the insulating material 114 via the electrostatic adsorption electrode 113.

[Power supply terminal]
The power supply terminal 116 is for applying a voltage to the electrostatic adsorption electrode 113.
The number, shape, and the like of the power feeding terminals 116 are determined by the form of the electrostatic adsorption electrode 113, that is, whether it is a unipolar type or a bipolar type.

The material of the power feeding terminal 116 is not particularly limited as long as it is a conductive material having excellent heat resistance. As the material of the power feeding terminal 116, it is preferable that the coefficient of thermal expansion is close to the coefficient of thermal expansion of the electrostatic adsorption electrode 113 and the support plate 112, and for example, a metal material such as Kovar alloy or niobium (Nb). , Various conductive ceramics are preferably used.

[Conductive adhesive layer]
The conductive adhesive layer 117 is provided in the fixing hole 115 of the temperature control base member 103 and in the through hole 118 of the support plate 112. Further, the conductive adhesive layer 117 is interposed between the electrostatic adsorption electrode 113 and the power supply terminal 116 to electrically connect the electrostatic adsorption electrode 113 and the power supply terminal 116.

The conductive adhesive constituting the conductive adhesive layer 117 contains a conductive substance such as carbon fiber and metal powder and a resin.

The resin contained in the conductive adhesive is not particularly limited as long as it is unlikely to cause cohesive failure due to thermal stress. For example, silicone resin, acrylic resin, epoxy resin, phenol resin, polyurethane resin, unsaturated polyester resin and the like. Can be mentioned.
Among these, silicone resin is preferable because it has high elasticity and is unlikely to coagulate and fracture due to changes in thermal stress.

[Temperature adjustment base member]
The temperature adjusting base member 103 is a thick disk made of at least one of metal and ceramics. The skeleton of the temperature adjusting base member 103 is configured to also serve as an internal electrode for plasma generation. Inside the skeleton of the temperature adjusting base member 103, a flow path 121 for circulating a cooling medium such as _{water, He gas, N 2 gas, etc. is formed.}

The skeleton of the temperature adjusting base member 103 is connected to an external high frequency power supply 122. Further, in the fixing hole 115 of the temperature adjusting base member 103, a power feeding terminal 116 whose outer periphery is surrounded by the insulating material 123 is fixed via the insulating material 123. The power supply terminal 116 is connected to an external DC power supply 124.

The material constituting the temperature adjusting base member 103 is not particularly limited as long as it is a metal having excellent thermal conductivity, conductivity, and workability, or a composite material containing these metals. As the material constituting the temperature adjusting base member 3, for example, aluminum (Al), copper (Cu), stainless steel (SUS), titanium (Ti) and the like are preferably used.
At least the surface of the temperature adjusting base member 103 exposed to plasma is preferably anodized or resin-coated with a polyimide resin. Further, it is more preferable that the entire surface of the temperature adjusting base member 103 is subjected to the above-mentioned alumite treatment or resin coating.

By applying an alumite treatment or a resin coating to the temperature adjusting base member 103, the plasma resistance of the temperature adjusting base member 103 is improved and abnormal discharge is prevented. Therefore, the plasma resistance stability of the temperature adjusting base member 103 is improved, and the occurrence of surface scratches on the temperature adjusting base member 103 can be prevented.

[Adhesive layer]
The adhesive layer 104 adheres and integrates the electrostatic chuck portion 102 and the cooling base portion 103.

The thickness of the adhesive layer 104 is preferably 100 μm or more and 200 μm or less, and more preferably 130 μm or more and 170 μm or less.
When the thickness of the adhesive layer 104 is within the above range, the adhesive strength between the electrostatic chuck portion 102 and the cooling base portion 103 can be sufficiently maintained. Further, it is possible to sufficiently secure the thermal conductivity between the electrostatic chuck portion 102 and the cooling base portion 103.

The adhesive layer 104 is formed of, for example, a cured product obtained by heat-curing a silicone-based resin composition, an acrylic resin, an epoxy resin, or the like.
The silicone-based resin composition is a silicon compound having a siloxane bond (Si—O—Si), and is more preferable because it is a resin having excellent heat resistance and elasticity.

As such a silicone-based resin composition, a silicone resin having a thermosetting temperature of 70 ° C. to 140 ° C. is particularly preferable.
Here, if the thermosetting temperature is lower than 70 ° C., when the electrostatic chuck portion 102 and the cooling base portion 103 are joined in a state of facing each other, the curing does not proceed sufficiently in the joining process, so that workability It is not preferable because it is inferior to. On the other hand, when the heat curing temperature exceeds 140 ° C., the difference in thermal expansion between the electrostatic chuck portion 102 and the cooling base portion 103 is large, and the stress between the electrostatic chuck portion 102 and the cooling base portion 103 increases. , It is not preferable because peeling may occur between them.

According to the electrostatic chuck device 100 of the present embodiment, since the electrostatic chuck member 102 is made of the ceramic joint 1, it is possible to suppress the occurrence of dielectric breakdown (discharge) in the electrostatic chuck member 102.

Hereinafter, a method of manufacturing the electrostatic chuck device of this embodiment will be described.

An electrostatic chuck member 102 made of the ceramic joint 1 obtained as described above is prepared.

An adhesive made of a silicone-based resin composition is applied to a predetermined region of one main surface 103a of the cooling base portion 103. Here, the amount of the adhesive applied is adjusted so that the electrostatic chuck portion 102 and the cooling base portion 103 can be joined and integrated.
Examples of the method for applying this adhesive include a bar coating method, a screen printing method, and the like, in addition to manually applying the adhesive using a spatula or the like.

After applying the adhesive to one main surface 103a of the cooling base portion 103, the electrostatic chuck portion 102 and the cooling base portion 103 coated with the adhesive are overlapped with each other.
Further, the standing power supply terminal 116 is inserted into and fitted into the fixing hole 115 formed in the cooling base portion 103.
Next, the electrostatic chuck portion 102 is pressed against the cooling base portion 103 with a predetermined pressure to join and integrate the electrostatic chuck portion 102 and the cooling base portion 103. As a result, the electrostatic chuck portion 102 and the cooling base portion 103 are joined and integrated via the adhesive layer 104.

As described above, the electrostatic chuck device 100 of the present embodiment is obtained in which the electrostatic chuck portion 102 and the cooling base portion 103 are joined and integrated via the adhesive layer 104.

The plate-shaped sample according to the present embodiment is not limited to a semiconductor wafer, and is, for example, a glass substrate for a flat plate display (FPD) such as a liquid crystal display (LCD), a plasma display (PDP), or an organic EL display. It may be. Further, the electrostatic chuck device of the present embodiment may be designed according to the shape and size of the substrate.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1]
"Manufacturing of ceramic joints"
A mixed powder of 91% by mass of aluminum oxide powder and 9% by mass of silicon carbide powder is molded and sintered, and is composed of a disk-shaped aluminum oxide-silicon carbide composite sintered body having a diameter of 450 mm and a thickness of 5.0 mm. Ceramic plates (first ceramic plate, second ceramic plate) were produced.
By the screen printing method, a paste for forming an intermediate layer was applied to one surface of the first ceramic plate to form a first intermediate layer coating film.
As the paste for forming the intermediate layer, a paste obtained by dispersing aluminum oxide powder in isopropyl alcohol was used. The content of the aluminum oxide powder in the paste for forming the intermediate layer was set to 50% by mass.
Next, the conductive layer forming paste is applied to the surface of the first intermediate layer coating film formed on one surface of the first ceramic plate by the screen printing method, which is opposite to the surface in contact with the first ceramic plate. , The conductive layer coating film is formed, and the surface of the first intermediate layer coating film formed on one surface of the first ceramic plate by the screen printing method is on the surface opposite to the surface in contact with the first ceramic plate. An insulating layer forming paste was applied to form an insulating layer coating film.
As the paste for forming the conductive layer, a paste obtained by dispersing aluminum oxide powder and molybdenum carbide powder in isopropyl alcohol was used. The content of the aluminum oxide powder in the paste for forming the conductive layer was 25% by mass, and the content of the molybdenum carbide powder was 25% by mass. As the paste for forming the insulating layer, aluminum oxide powder having an average primary particle size of 2.0 μm was dispersed in isopropyl alcohol. The content of the aluminum oxide powder in the paste for forming the insulating layer was set to 50% by mass.
Then, by the screen printing method, the surface of the conductive layer coating film on the side opposite to the surface in contact with the first intermediate layer coating film and the surface of the insulating layer coating film on the side opposite to the surface in contact with the first intermediate layer coating film. The above intermediate layer forming paste was applied to the surface to form a second intermediate layer coating film.
Next, the second ceramic plate was laminated on the surface of the second intermediate layer coating film on the side opposite to the surface in contact with the conductive layer coating film and the insulating layer coating film.
Next, the laminate including the first ceramic plate, the first intermediate layer coating film, the conductive layer coating film, the insulating layer coating film, the second intermediate layer coating film and the second ceramic plate is heated under an argon atmosphere. While pressurizing in the thickness direction. The heat treatment temperature was 1700 ° C., the pressing force was 10 MPa, and the heat treatment and pressurizing time was 2 hours.
Through the above steps, the ceramic joint of Example 1 as shown in FIG. 1 was obtained. In the obtained ceramic joint, the ratio of the total thickness of the first intermediate layer and the thickness of the second intermediate layer t2 to the thickness t1 of the conductive layer defined by the following formula (1) (R1). Was 4%.
R1 = t2 / t1 × 100 (%) (1)

(Insulation evaluation)
The insulation of the ceramic joint was evaluated as follows.
In contact with the first ceramic plate, the first intermediate layer, the conductive layer, the insulating layer, the second intermediate layer and the second ceramic plate on the side surface of the ceramic joint (the side surface in the thickness direction of the ceramic joint). A carbon tape was attached to.
Through electrodes that penetrate the first ceramic plate and the first intermediate layer in the thickness direction of the first ceramic plate and reach the conductive layer from the surface opposite to the surface of the first ceramic plate in contact with the first intermediate layer. Formed.
A voltage was applied to the ceramic joint via the carbon tape and the through electrode, and the voltage at which the ceramic joint breaks down was measured. Specifically, with a voltage of 3000 V applied, an RF voltage was applied and held for 10 minutes, then a voltage of 500 V was gradually applied and held for 10 minutes, and the measured current value was 0.1 mA (milliampere). The place beyond the above was defined as dielectric breakdown. The results are shown in Table 1.

[Example 2]
The average primary particle size of the aluminum oxide powder contained in the insulating layer is 3.0 μm, and the first ceramic plate, the first intermediate layer coating film, the conductive layer coating film, the insulating layer coating film, and the second intermediate layer coating film are used. The ceramic joint of Example 2 was obtained in the same manner as in Example 1 except that the heat treatment temperature of the laminate containing the second ceramic plate was set to 1750 ° C.
In the same manner as in Example 1, the insulating property of the ceramic joint of Example 2 was evaluated. The results are shown in Table 1.

[Example 3]
A ceramic composite of Example 2 was obtained in the same manner as in Example 1 except that the average primary particle size of the aluminum oxide powder contained in the insulating layer was 1.9 μm. In the obtained ceramic joint, the ratio (R1) of the total thickness of the first intermediate layer and the thickness of the second intermediate layer t2 to the thickness t1 of the conductive layer was 8%.
In the same manner as in Example 1, the insulating property of the ceramic joint of Example 3 was evaluated. The results are shown in Table 1.

[Example 4]
The average primary particle size of the aluminum oxide powder contained in the insulating layer is 3.3 μm, and the first ceramic plate, the first intermediate layer coating film, the conductive layer coating film, the insulating layer coating film, and the second intermediate layer coating film are used. The ceramic joint of Example 4 was obtained in the same manner as in Example 1 except that the heat treatment temperature of the laminate containing the second ceramic plate was set to 1750 ° C. In the obtained ceramic joint, the ratio (R1) of the total thickness of the first intermediate layer and the thickness of the second intermediate layer t2 to the thickness t1 of the conductive layer was 8%.
In the same manner as in Example 1, the insulating property of the ceramic joint of Example 4 was evaluated. The results are shown in Table 1.

[Example 5]
The average primary particle size of the aluminum oxide powder contained in the insulating layer is 5.8 μm, and the first ceramic plate, the first intermediate layer coating film, the conductive layer coating film, the insulating layer coating film, and the second intermediate layer coating film are used. The ceramic joint of Example 5 was obtained in the same manner as in Example 1 except that the heat treatment temperature of the laminate containing the second ceramic plate was set to 1800 ° C. In the obtained ceramic joint, the ratio (R1) of the total thickness of the first intermediate layer and the thickness of the second intermediate layer t2 to the thickness t1 of the conductive layer was 13%.
In the same manner as in Example 1, the insulating property of the ceramic joint of Example 5 was evaluated. The results are shown in Table 1.

[Comparison example]
Similar to Example 1 except that the first intermediate layer and the second intermediate layer were not provided and the average primary particle size of the aluminum oxide powder contained in the insulating layer was 1.5 μm. A ceramic joint was obtained.
In the same manner as in Example 1, the insulating properties of the ceramic joints of Comparative Examples were evaluated. The results are shown in Table 1.

From the results in Table 1, it was found that the ceramic joints of Comparative Examples having no intermediate layer had a low insulation withstand voltage, but the ceramic joints of Examples 1 to 5 having an intermediate layer had a high insulation withstand voltage. .. Further, the larger the average primary particle size of the aluminum oxide powder used for the insulating layer, the higher the dielectric strength (comparison between Examples 1 and 2 and Examples 3 and 4). It is considered that this is because the grain boundary phase having low insulating property is reduced by coarse-graining the aluminum oxide particles.

The ceramic joint of the present invention has an intermediate layer that is interposed between the ceramic plate and the conductive layer and is in contact with the ceramic plate and the conductive layer, and dielectric breakdown (discharge) occurs at the joint interface between the ceramic plate and the conductive layer. Is suppressed. Therefore, the ceramic joint of the present invention is suitably used as an electrostatic chuck member of an electrostatic chuck device, and its usefulness is very great.

1,10 Ceramic joint 2 Ceramic plate (first ceramic plate)
3 Ceramic plate (second ceramic plate)
4 Conductive layer 5 Insulation layer 6 Intermediate layer (first intermediate layer)
7 Middle layer (second middle layer)
100 Electrostatic Chuck Device 102 Electrostatic Chuck Member 103 Temperature Control Base Member 104 Adhesive Layer 111 Mounting Plate 112 Support Plate 113 Electrostatic Adsorption Electrode 114 Insulating Material 115 Fixing Hole 116 Power Supply Terminal 117 Conductive Adhesive Layer 118 Penetration Hole 121 Flow path 122 High frequency power supply 123 Insulation material 124 DC power supply

Claims (9)

A pair of ceramic plates containing a conductive substance, a conductive layer and an insulating layer interposed between the pair of ceramic plates, and the pair of ceramic plates and the conductive layer interposed between the pair of ceramic plates and the conductive layer. A ceramic joint comprising an intermediate layer in contact with. The ceramic joint according to claim 1, wherein the conductive layer is made of a conductive substance and an insulating substance, and the insulating layer and the intermediate layer are made of an insulating substance. Claim 1 or 2 in which the thickness ratio R1 of the intermediate layer defined by the following formula (1) is 3% or more, where t1 is the thickness of the conductive layer and t2 is the thickness of the intermediate layer. The ceramic joint according to.
R1 = t2 / t1 × 100 (%) (1) The ceramic joint according to any one of claims 2 or 3, wherein the average primary particle size of the insulating substance constituting the insulating layer is 1.6 μm or more and 10.0 μm or less. The ceramic joint according to any one of claims 1 to 4, wherein the ceramic plate is a composite of aluminum oxide and silicon carbide. The ceramic joint according to any one of claims 2 to 5, wherein the conductive layer, the insulating layer, and the insulating substance constituting the intermediate layer are aluminum oxide. The conductive substance constituting the conductive layer _{is at least one selected from the group consisting of Mo 2} C, Mo, WC, W, TaC, Ta, SiC, carbon black, carbon nanotubes and carbon nanofibers. The ceramic joint according to any one of 2 to 6. An electrostatic chuck device in which an electrostatic chuck member made of ceramics and a temperature control base member made of metal are joined via an adhesive layer.
The electrostatic chuck member is an electrostatic chuck device made of the ceramic joint according to any one of claims 1 to 7. A step of applying a paste for forming an intermediate layer to one surface of a first ceramic plate containing a conductive substance to form a first intermediate layer coating film, and a step of forming the first intermediate layer coating film.
A step of applying a conductive layer forming paste to a surface of the first intermediate layer coating film opposite to the surface in contact with the first ceramic plate to form a conductive layer coating film.
A step of applying the intermediate layer forming paste to the surface of the conductive layer coating film on the side opposite to the surface in contact with the first intermediate layer coating film to form the second intermediate layer coating film.
A step of laminating a second ceramic plate containing a conductive substance on a surface of the second intermediate layer coating film opposite to the surface in contact with the conductive layer coating film.
While heating the laminate containing the first ceramic plate, the first intermediate layer coating film, the conductive layer coating film, the second intermediate layer coating film, and the second ceramic plate, in the thickness direction. A method for manufacturing a ceramic joint having a step of pressurizing.

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